If you are talking about your WiFi dropping out then yes changing the channel may help. The instructions on how to do this vary depending on the modem so if the links below don't help you will need to tell us the make and model of your modem.

I have tried to change the channel with the numbers I was given by Optus. But I think they have made a mistake as it is not working. I have a router and modem. They told me to type in the numbers they gave me, then I typed in the username and password on the base of the modem, but it didn’t work. Also the numbers they gave me don’t match the ones on the base of the modem. And what about the numbers on the router? Is there a technician that can come and sort this out for me, as it’s been going on for a while now. Our next door neighbours are with Optus and perhaps they are on the same channel. The modem/router we have are new, and don’t they automatically change channels if it’s busy?

I am very unhappy with this, as we had no trouble before getting the new modem/router.

So you have 2 devices as in a separate modem and router? That being the case and depending on how they are configured you may be trying to access the wrong device. Have a look under the second device for the Administration address and password. It should look something like http://192.168.8.1 Failing that your local computer store should be able to help you with that.

Every modern internet browser should automatically add the http:// part of the address for you so all you have to do is type out the numbers including the dots. If you get an error message saying the page cant be found then either the address is wrong or you have not typed it out correctly. Do you have 2 separate modems or just the one? Can you tell me what the name, make or model is as that really would be helpful.

Edit: Once you type the address out correctly you should then be asked for the username and password to access the settings. That is the information on the bottom of the modem.

You need to be connected to the router for this to work so turn Mobile data off on your iPad and make sure you are connected to your router via WiFi. Go to Settings / WiFi and tap on your current connection. This should bring up a page that looks like second picture below. Open up Safari and type that number into the address box at the top and hit Go.

I already have that number. We have two iPads with no mobile data, but our phones do. They all use the WiFi. Should I turn of mobile data on both phones? If this works, can I turn the data back on the phones afterwards?